arch/arm/nwfpe/fpa11.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3     NetWinder Floating Point Emulator
   4     (c) Rebel.com, 1998-1999
   5
   6     Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
   7
   8 */
   9
  10 #ifndef __FPA11_H__
  11 #define __FPA11_H__
  12
  13 #define GET_FPA11() ((FPA11 *)(&current_thread_info()->fpstate))
  14
  15 /*
  16  * The processes registers are always at the very top of the 8K
  17  * stack+task struct.  Use the same method as 'current' uses to
  18  * reach them.
  19  */
  20 #define GET_USERREG() ((struct pt_regs *)(THREAD_START_SP + (unsigned long)current_thread_info()) - 1)
  21
  22 #include <linux/thread_info.h>
  23
  24 /* includes */
  25 #include "fpsr.h"               /* FP control and status register definitions */
  26 #include "milieu.h"
  27
  28 struct roundingData {
  29     int8 mode;
  30     int8 precision;
  31     signed char exception;
  32 };
  33
  34 #include "softfloat.h"
  35
  36 #define         typeNone                0x00
  37 #define         typeSingle              0x01
  38 #define         typeDouble              0x02
  39 #define         typeExtended            0x03
  40
  41 /*
  42  * This must be no more and no less than 12 bytes.
  43  */
  44 typedef union tagFPREG {
  45         float32 fSingle;
  46         float64 fDouble;
  47 #ifdef CONFIG_FPE_NWFPE_XP
  48         floatx80 fExtended;
  49 #else
  50         u32 padding[3];
  51 #endif
  52 } __attribute__ ((packed,aligned(4))) FPREG;
  53
  54 /*
  55  * FPA11 device model.
  56  *
  57  * This structure is exported to user space.  Do not re-order.
  58  * Only add new stuff to the end, and do not change the size of
  59  * any element.  Elements of this structure are used by user
  60  * space, and must match struct user_fp in <asm/user.h>.
  61  * We include the byte offsets below for documentation purposes.
  62  *
  63  * The size of this structure and FPREG are checked by fpmodule.c
  64  * on initialisation.  If the rules have been broken, NWFPE will
  65  * not initialise.
  66  */
  67 typedef struct tagFPA11 {
  68 /*   0 */ FPREG fpreg[8];       /* 8 floating point registers */
  69 /*  96 */ FPSR fpsr;            /* floating point status register */
  70 /* 100 */ FPCR fpcr;            /* floating point control register */
  71 /* 104 */ unsigned char fType[8];       /* type of floating point value held in
  72                                            floating point registers.  One of
  73                                            none, single, double or extended. */
  74 /* 112 */ int initflag;         /* this is special.  The kernel guarantees
  75                                    to set it to 0 when a thread is launched,
  76                                    so we can use it to detect whether this
  77                                    instance of the emulator needs to be
  78                                    initialised. */
  79 } __attribute__ ((packed,aligned(4))) FPA11;
  80
  81 extern int8 SetRoundingMode(const unsigned int);
  82 extern int8 SetRoundingPrecision(const unsigned int);
  83 extern void nwfpe_init_fpa(union fp_state *fp);
  84
  85 extern unsigned int EmulateAll(unsigned int opcode);
  86
  87 extern unsigned int EmulateCPDT(const unsigned int opcode);
  88 extern unsigned int EmulateCPDO(const unsigned int opcode);
  89 extern unsigned int EmulateCPRT(const unsigned int opcode);
  90
  91 /* fpa11_cpdt.c */
  92 extern unsigned int PerformLDF(const unsigned int opcode);
  93 extern unsigned int PerformSTF(const unsigned int opcode);
  94 extern unsigned int PerformLFM(const unsigned int opcode);
  95 extern unsigned int PerformSFM(const unsigned int opcode);
  96
  97 /* single_cpdo.c */
  98
  99 extern unsigned int SingleCPDO(struct roundingData *roundData,
 100                                const unsigned int opcode, FPREG * rFd);
 101 /* double_cpdo.c */
 102 extern unsigned int DoubleCPDO(struct roundingData *roundData,
 103                                const unsigned int opcode, FPREG * rFd);
 104
 105 /* extneded_cpdo.c */
 106 extern unsigned int ExtendedCPDO(struct roundingData *roundData,
 107                                  const unsigned int opcode, FPREG * rFd);
 108
 109 #endif